<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style type="text/css">
        .box1
        {
            width: 300px;
            height: 100px;
            padding-right: 10px;
            margin-right: 10px;
            background: #F90;
            border:10px solid #ccc;
            box-sizing:content-box;
        }
    </style>
</head>
<body>
    <div class="box1">sadflkas dfasldfjsalf</div>
</body>
</html>